94 BUTANICAL GAZETTE [ AUGUST 
numbers by splitting, is of interest. His evidence for the hypothe 
sis may be statedas follows: (1) the apparent rapid increase in 
the number of fibers; (2) the fibers produce a rapid outgrowth 
of the cell plate; (3) they are often found lying closely side by 
side. The first and third points seem to me to be readily 
explained by the facts that I have already described for the 
larch, viz., the rearrangement of the fibers by the bundles 
separating into single fibers, and the shortening and thickening 
of the fibers, resulting in a spindle of denser appearance, with 
apparently more numerous fibers. Strasburger himself points 
out that the spindle fibers seem to separate from the daughte! 
nuclei and to become thicker and more densely stained prior to 
the formation of a cell plate. It should be noted, however, that 
Strasburger had previously accepted Guignard’s doctrine thé! 
the connecting fibers are secondary structures formed by tht 
fusion of smaller primary fibers. The splitting of the fibers, it 
Strasburger’s sense, would be essentially the same as the sepat# 
tion of fibers, as described above, with this one exception: # 
the former case the process is unlimited, for new fibers may ©” 
tinuously arise by the splitting of original fibers, but in the 
latter the process is limited by the number of fibers making 
the bundles. If the splitting hypothesis were true, it W a 
explain, as Strasburger suggested, the appearance of 14 & 
peripheral connecting fibers, and thereby the growth of the cell 
plate; but below I shall describe phenomena which seem vo 
indicate that the appearance of new peripheral fibers depends 
not upon such a multiplication of the original connecting fibers, 
but upon changes in some of the radiating fibers. - 
Concurrent with the above described changes in the commer | 
the previously described radiating fibers is evident from 4 care , 
ful study of the preparations. In fig. 261 have drawn accuratel) : 
two such fibers extending one from each nucleus. Heré 
